> ## Documentation Index
> Fetch the complete documentation index at: https://docs.metriport.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Observation

> Schema documentation for the Observation table in the Metriport data model

The observation resource is used to support diagnosis, monitor progress, determine baselines and patterns and even capture demographic characteristics.

**Reference Table:**

The `observation_references` table contains normalized references from the observation to other entities. It supports the following reference properties:

* **subject** (required): links to the patient who is the subject of the observation
* **encounter**: links to the encounter where the observation was made
* **performer**: links to practitioners who performed the observation

For detailed information about reference table structure and indexing, see the [Reference Tables documentation](/medical-api/handling-data/schema-v000/reference-tables).

**Observation Table:**

**Primary Keys:**

* observation\_id

**Foreign Keys:**

* patient\_id

| Column | Data Type | Description |
| - | - | - |
| observation\_id | varchar | Unique identifier for the observation |
| patient\_id | varchar | Unique identifier for the patient |
| status | varchar | Status of the observation. Possible values:<br />– <code>registered</code>: The existence of the observation is registered, but there is no result yet available.<br />– <code>preliminary</code>: This is an initial or interim observation: data may be incomplete or unverified.<br />– <code>final</code>: The observation is complete and verified by an authorized person.<br />– <code>amended</code>: Subsequent to being final, the observation has been modified; the current version is complete and verified.<br />– <code>corrected</code>: Subsequent to being final, the observation has been modified to correct an error in the result.<br />– <code>cancelled</code>: The observation is unavailable because the measurement was not started or not completed.<br />– <code>entered-in-error</code>: The observation has been withdrawn following erroneous entry.<br />– <code>unknown</code>: The authoring/source system does not know the current status of the observation. |
| effective\_date | date | Start date of the observation |
| end\_date | date | End date of the observation |
| loinc\_code | varchar | LOINC code for the observation |
| loinc\_display | varchar | Human-readable description of LOINC code |
| source\_code\_code | varchar | Original code from source system |
| source\_code\_display | varchar | Original code display from source system |
| source\_code\_system | varchar | Original code system from source system |
| value | varchar | Value of the observation |
| units | varchar | Unit of measurement |
| reference\_range\_low | varchar | Lower bound of the reference range |
| reference\_range\_high | varchar | Upper bound of the reference range |
| category\_hl7\_code | varchar | HL7 category code |
| category\_hl7\_display | varchar | Human-readable description of HL7 category |
| interpretation\_hl7\_code | varchar | HL7 interpretation code |
| interpretation\_hl7\_display | varchar | Human-readable description of HL7 interpretation |
| bodysite\_snomed\_ct\_code | varchar | SNOMED CT body site code |
| bodysite\_snomed\_ct\_display | varchar | Human-readable description of SNOMED CT body site |
| note\_text | varchar | Additional notes about the observation |
| meta\_source | varchar | Source document filename from FHIR meta.source |
| data\_source | varchar | **Deprecated.** Use `meta_source` instead. |
| data\_source\_ext | varchar | Integration source of the data, derived from FHIR extension |


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